All skin treatments based on light either with lasers or IPL (Intense Pulse Light) by thermolysis require delicate energy control in case to gain effective treatment without causing damage to the skin.
In commercial IPL systems, the energy is controlled either by controlling the pulse width of the light with very strong and expensive components or by means of energy measurements done with expensive components. The components that control the width of the pulse have to switch on and off the high voltage and the high current that operate the flash lamps. Usually the systems use IGBTs (Insulated Gate Bipolar Transistors) or MOSFETs (Metal-Oxide Semiconductor Field-Effect Transistors) for switching thousands of volts and amperes, and these components are big, expensive and very delicate in design. The thermal disc that measures the energy in order to control the energy is very expensive and must be cooled.